had been grazed by all those shad in the Holyoke Pool. So my hypothesis is that what keeps these guys going farther and farther, when there are clear disadvan- tages to doing so, has to be an advantage for progen)T. And the one advantage to progeny that we have documented is that there's more food--zooplankton- upstream for concentrations of juvenile shad than there is downstream. So, put your offspring at the head of the chow line. This hypothesis relies on the very well-documented fact that the larger you are as a prey species the better off you are. Even one extra millimetre will con- fer a survival advantage to you in the face of predation. When juvenile shad move down the river, they're subject to all sorts of riverine predators that eat them-smallmouth bass in particular." "What else eats them?" "Walleyes. White perch. Stripers. These guys-the juvenile shad-are coming down by the hundreds of mil- lions, and they're all very tender and bite size." In spring, sexually mature shad be- gin to enter their home rivers when the water temperature reaches about four to six degrees Celsius (about forty Fahren- heit), and they spawn when the temper- ature is between sixteen and twenty-two (sixty to seventy Fahrenheit). So, in ef- fect, they have brackets around them. In the Connecticut River, they have, on average, forty-five days to make their run and complete the ritual sexing of their eggs. In Kynard's words, "When they enter a river, the clock is ticking. They have varying degrees of energy, varying de- grees of swimming abilitJ They're not feeding, so they have an unrenewable energy reserve that will take them only so far up the river, depending also on de- lays, water velocity (how hard they have to swim to get there), and water temper- ature. It is fairly well established that when water temperature gets to twenty- one they slow down, and by twenty-two they stop. They look for a suitable place to spawn. It's a race against time. If you're a shad, you take every opportunity to get as far upstream as you can, past every obstacle, before the water temper- ature reaches twenty-one degrees. The joker is that you never know what the environment is going to throw at you. You can have the fifty-year flood. You can 76 THE NEW YORKER., SEPTEMBER 11,2000 have low water. Through it all, you have to keep going, and go as fast and as far upstream as you can, because that's the only way your offspring have any chance to have an advantage." When the Delaware River is just honkin', I told him, I have discovered that I can catch shad on people's lawns. After extreme and sustained rains- water over the banks-the center of the stream is a lethal rage of gray rolling waves. A couple of hundred miles above Philadelphia, I'm standing on some- body's lawn, in fairly calm but turbid water three feet deep. This is not quix- otic. The fish-completely frustrated, anxious to go as far as possible-are up on the lawn, too. Kynard explains: "Come a big rain, the whole migration will stop for two weeks. Trying to save energy in slow water, they aren't doing anything-they're just hanging on. Out in the river, not only is the current heavy but turbidity is such that the shad can't go to the low slow water, because there's not enough light down there. They have no choice. They have to hang out way over to the side, maintain position, and just hope like hell it doesn't keep raining." O ut of our waders and into Kynard's office, we had been through a fair amount of this dialogue at the S. O. Conte Anadromous Fish Research Cen- ter, in Turners Falls, a small community in northern Massachusetts enabled by a dam built in 1798 at a natural pitch of the Connecticut River. Built to intercept logs, it also blocked the migration of fish, setting a fateful precedent as the :first main-stem dam on a major river in North America. Thomas & Thomas bamboo fly rods are made at the intake end of the power canal there, and the Conte lab, two miles down, is not far :&om a generating station where the canal water spills through turbines and back to the river. Below Thomas & Thomas, a modest cluster of antique industrial structures soon gives way to open ground, forested at the edges, in which the swift current of the canal slows and spreads into something like a lake, flanked by a road but-in the better part of a mile-only a low pair of buildings, the seventeen- million-dollar Conte lab, nestled into the canal's right bank. Named in part for Sil- vio Conte, the Massachusetts congress- man who made it happen, the lab was 5HOWCA5E BY FIR.OOZ ZAHEDI DOG STAR C hristopher Guest, the mockumentarian (he created the role of Nigel T ufnel, lead guitarist in "This Is Spinal Tap"), writes intricate scenarios for his actors, giving them motives, backgrounds, and outlines of marital dynamics-but no dialogue. "What sounds like a haphazard approach is just the opposite," Guest says. "The actors are so skilled in this way of working" -they ad -lib in character, and he shoots the results-"it's like having talented jazz players improvising. We know when the solos are coming." The actors love it-practically the whole cast :&om "Waiting for Guffman," his 1997 feature about a small Missouri town's sesquicentennial play; returned for his latest effort, "Best in Show," which follows five dogs and their owners through the Mayflower Dog Show. The actors prepped with professional handlers to learn the trade secrets of leash work in the show ring. Guest invented a brisk, stiff-legged presentation lope that made his character, Harlan Pepper, appear eerily one with his bloodhound, Hubert. "I subscribed to American Cooner, something I'm sure you get as well," Guest says. ' d I started to become enlightened, if that's the right word." His heartfelt ode to the breed, delivered in a thick- as-pine-tar North Carolina accent, is one of the film's comic highlights. The idea for the work (which premières this week at the Toronto International Film Festival) came to him when he and his wife, Jamie Lee Curtis, took their mutts, Henry and Lucy; to the local dog park, where they found poodle people disparaging the pugs, and pug people returning the favor. "There was an almost religious overtone tQ it," Guest says. "It became practically a microcosm of race and religion." -Kevin Conley